[patch] clone-cleanup 2.5.32-BK

From: Ingo Molnar (mingo@elte.hu)
Date: Fri Aug 30 2002 - 02:26:25 EST

the attached patch moves CLONE_SETTID and CLONE_CLEARTID handling into
kernel/fork.c, where it belongs. [the CLONE_SETTLS is x86-specific and
thus remains in the per-arch process.c] This makes support for these two
new flags much easier: architectures only have to pass in the user_tid
pointer. (I tested the patch with userspace threading code and it works
just fine.)

        Ingo

--- linux/arch/i386/kernel/smpboot.c.orig Fri Aug 30 09:20:52 2002
+++ linux/arch/i386/kernel/smpboot.c Fri Aug 30 09:20:59 2002
@@ -495,7 +495,7 @@
          * don't care about the eip and regs settings since
          * we'll never reschedule the forked task.
          */
- return do_fork(CLONE_VM|CLONE_IDLETASK, 0, &regs, 0);
+ return do_fork(CLONE_VM|CLONE_IDLETASK, 0, &regs, 0, NULL);
 }
 
 /* which physical APIC ID maps to which logical CPU number */
--- linux/arch/i386/kernel/process.c.orig Fri Aug 30 09:14:27 2002
+++ linux/arch/i386/kernel/process.c Fri Aug 30 09:20:32 2002
@@ -504,7 +504,7 @@
         regs.eflags = 0x286;
 
         /* Ok, create the new process.. */
- p = do_fork(flags | CLONE_VM, 0, &regs, 0);
+ p = do_fork(flags | CLONE_VM, 0, &regs, 0, NULL);
         return IS_ERR(p) ? PTR_ERR(p) : p->pid;
 }
 
@@ -588,11 +588,6 @@
         }
 
         /*
- * The common fastpath:
- */
- if (!(clone_flags & (CLONE_SETTLS | CLONE_SETTID | CLONE_CLEARTID)))
- return 0;
- /*
          * Set a new TLS for the child thread?
          */
         if (clone_flags & CLONE_SETTLS) {
@@ -613,19 +608,6 @@
                 desc->a = LDT_entry_a(&info);
                 desc->b = LDT_entry_b(&info);
         }
-
- /*
- * Notify the child of the TID?
- */
- if (clone_flags & CLONE_SETTID)
- if (put_user(p->pid, (pid_t *)childregs->edx))
- return -EFAULT;
-
- /*
- * Does the userspace VM want the TID cleared on mm_release()?
- */
- if (clone_flags & CLONE_CLEARTID)
- p->user_tid = (int *) childregs->edx;
         return 0;
 }
 
@@ -779,7 +761,7 @@
 {
         struct task_struct *p;
 
- p = do_fork(SIGCHLD, regs.esp, &regs, 0);
+ p = do_fork(SIGCHLD, regs.esp, &regs, 0, NULL);
         return IS_ERR(p) ? PTR_ERR(p) : p->pid;
 }
 
@@ -788,12 +770,14 @@
         struct task_struct *p;
         unsigned long clone_flags;
         unsigned long newsp;
+ int *user_tid;
 
         clone_flags = regs.ebx;
         newsp = regs.ecx;
+ user_tid = (int *)regs.edx;
         if (!newsp)
                 newsp = regs.esp;
- p = do_fork(clone_flags & ~CLONE_IDLETASK, newsp, &regs, 0);
+ p = do_fork(clone_flags & ~CLONE_IDLETASK, newsp, &regs, 0, user_tid);
         return IS_ERR(p) ? PTR_ERR(p) : p->pid;
 }
 
@@ -811,7 +795,7 @@
 {
         struct task_struct *p;
 
- p = do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.esp, &regs, 0);
+ p = do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.esp, &regs, 0, NULL);
         return IS_ERR(p) ? PTR_ERR(p) : p->pid;
 }
 
--- linux/include/linux/sched.h.orig Fri Aug 30 09:14:48 2002
+++ linux/include/linux/sched.h Fri Aug 30 09:17:44 2002
@@ -659,7 +659,7 @@
 extern task_t *child_reaper;
 
 extern int do_execve(char *, char **, char **, struct pt_regs *);
-extern struct task_struct *do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long);
+extern struct task_struct *do_fork(unsigned long, unsigned long, struct pt_regs *, unsigned long, int *);
 
 extern void FASTCALL(add_wait_queue(wait_queue_head_t *q, wait_queue_t * wait));
 extern void FASTCALL(add_wait_queue_exclusive(wait_queue_head_t *q, wait_queue_t * wait));
--- linux/kernel/fork.c.orig Fri Aug 30 09:12:13 2002
+++ linux/kernel/fork.c Fri Aug 30 09:18:58 2002
@@ -649,7 +649,8 @@
 static struct task_struct *copy_process(unsigned long clone_flags,
                             unsigned long stack_start,
                             struct pt_regs *regs,
- unsigned long stack_size)
+ unsigned long stack_size,
+ int *user_tid)
 {
         int retval;
         struct task_struct *p = NULL;
@@ -760,7 +761,20 @@
         retval = copy_thread(0, clone_flags, stack_start, stack_size, p, regs);
         if (retval)
                 goto bad_fork_cleanup_namespace;
-
+ /*
+ * Notify the child of the TID?
+ */
+ retval = -EFAULT;
+ if (clone_flags & CLONE_SETTID)
+ if (put_user(p->pid, user_tid))
+ goto bad_fork_cleanup_namespace;
+
+ /*
+ * Does the userspace VM want the TID cleared on mm_release()?
+ */
+ if (clone_flags & CLONE_CLEARTID)
+ p->user_tid = user_tid;
+
         /* Our parent execution domain becomes current domain
            These must match for thread signalling to apply */
            
@@ -876,11 +890,12 @@
 struct task_struct *do_fork(unsigned long clone_flags,
                             unsigned long stack_start,
                             struct pt_regs *regs,
- unsigned long stack_size)
+ unsigned long stack_size,
+ int *user_tid)
 {
         struct task_struct *p;
 
- p = copy_process(clone_flags, stack_start, regs, stack_size);
+ p = copy_process(clone_flags, stack_start, regs, stack_size, user_tid);
         if (!IS_ERR(p)) {
                 struct completion vfork;
 

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